Let's set up a cool cluster of Ubuntu 12.04LTS 64-bit servers.

setup-some-servers.md

Note: All steps assume you are running Ubuntu 12.04LTS 64-bit servers. Most of these steps should apply to any distribution of Ubuntu, however.

App Servers

Steps

1. apt-get update
2. apt-get upgrade
3. apt-get install build-essential
4. apt-get install sqlite3 libsqlite3-ruby libsqlite3-dev
5. apt-get install libyaml-dev
6. apt-get install libpq-dev
7. apt-get install git
8. curl -L get.rvm.io | bash -s stable
9. source /etc/profile.d/rvm.sh
10. rvm reload
11. rvm install 2.1.0
12. apt-get install nodejs
13. gem install bundler rails
14. gem install unicorn
15. Add to ~/.bashrc:

source /etc/profile.d/rvm.sh
rvm reload

Manual App Setup

1. cd /var
2. mkdir www
3. cd www

application needs to have a pids directory

Clone App Repo

1. cd /var/www
2. git clone <app_repo>

Unicorn Config

1. vi config/unicorn.rb
2. Add the following:

working_directory "/var/www/<app_dir_name>"

pid "/var/www/<app_dir_name>/pids/unicorn.pid"

stderr_path "/var/www/<app_dir_name>/log/unicorn.log"
stdout_path "/var/www/<app_dir_name>/log/unicorn.log"

worker_processes 2

timeout 30

Migrate Database

1. rake db:migrate RAILS_ENV=<production/development>

Start Unicorn

1. unicorn_rails -c config/unicorn.rb -D -E production/development

Add Server IP to Load Balancer Server

1. ifconfig and add IP Address to /etc/nginx/nginx.conf on Load Balancer server

Random Capistrano Tidbits

1. default_run_options[:pty] = true

Server Hardening

On Server

1. useradd -s /bin/bash -G sudo -m <username>
2. passwd <username> (Enter password when prompted.)

Locally

1. ssh-copy-id -i ~/.ssh/id_rsa.pub <username@remote-host>
2. ssh <username@remote-host>

On Server

1. sudo nano /etc/ssh/sshd_config
2. Change PermitRootLogin yes to PermitRootLogin no
3. sudo restart ssh

Database Server

Steps

1. apt-get update
2. apt-get upgrade
3. apt-get install build-essential
4. apt-get install git
5. vi /etc/apt/sources.list.d/pgdg.list
6. deb http://apt.postgresql.org/pub/repos/apt/ precise-pgdg main (Note: replace precise with name of Ubuntu release. Get your current release name by typing lsb_release -c.)
7. apt-get update
8. apt-get upgrade
9. Potential error handling:

apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 7FCC7D46ACCC4CF8

11. apt-get install postgresql-9.3 pgadmin3
12. sudo -u postgres psql postgres
13. On psql command line:

• \password postgres and set password.
• \q to quit

Set Up Database and Roles

1. sudo -u postgres psql
2. On psql command line:

• CREATE USER <user_name> WITH PASSWORD '[password]';
• CREATE DATABASE <database_name> OWNER <user_name>;
• \q to quit

3. vi /etc/postgresql/9.3/main/postgresql.conf
4. Find line: #listen_addresses = 'localhost' and change to: listen_addresses = '*'
5. vi /etc/postgresql/9.3/main/pg_hba.conf
6. Find section: # Put your Actual configuration here
7. After comment block:

# TYPE   DATABASE      USER        ADDRESS        METHOD
host        all        all        0.0.0.0/0        md5

8. service postgresql restart

Configuring the Rails App

1. Edit config/database.yml:

production:
  adapter: postgresql
  encoding: utf8
  database: <database_name>
  username: <database_username>
  password: <password>
  host: <host_ip_address>
  port: 5432
  pool: 10

2. Edit Gemfile:

• gem 'pg'
• bundle

Load Balancer

Steps

1. apt-get update
2. apt-get upgrade
3. apt-get install build-essential
4. apt-get install nginx
5. useradd nginx --no-create-home
6. vi /etc/nginx/nginx.conf and replace with:

# For more information on configuration, see:
#   * Official English Documentation: http://nginx.org/en/docs/
#   * Official Russian Documentation: http://nginx.org/ru/docs/

user              nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log;
#error_log  /var/log/nginx/error.log  notice;
#error_log  /var/log/nginx/error.log  info;

pid        /var/run/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

    # Load config files from the /etc/nginx/conf.d directory
    # The default server is in conf.d/default.conf
    # include /etc/nginx/conf.d/*.conf;

    upstream unicorn_servers {
        server 172.31.32.79:8080 fail_timeout=0;
    }
  
    server {
        listen 80;

        location / {
            proxy_set_header        Host $host;
            proxy_set_header        X-Real-IP $remote_addr;
            proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;

            proxy_pass http://unicorn_servers;
        }
    }
}

7. Update server list under upstream unicorn_servers
8. service nginx start
9. If error, add types_hash_max_size 2048; in http section and resave.
10. service nginx restart

Tune Those Servers